JP5932916B2 - Inductor and manufacturing method thereof - Google Patents

Description

The present invention relates to an inductor and a manufacturing method thereof.

An inductor is one of the important passive elements that form an electronic circuit together with a resistor and a capacitor, and is used in various systems and components such as a low-noise amplifier, a mixer, a voltage-controlled oscillator, and a matching coil.

Such inductors can be classified into wire-wound inductors, laminated inductors, thin-film inductors, and the like according to their structures.

The wire-wound inductor can be formed by winding a coil around a ferrite core or the like.

Since the above-described wire-wound inductor can generate stray capacitance between the coils, the number of windings of the coil must be increased in order to obtain a high-capacity inductance. However, when the number of windings of the coil increases, there is a problem that high frequency characteristics deteriorate.

The multilayer inductor can be formed by laminating a plurality of ceramic sheets.

In the multilayer inductor, a coil-shaped metal pattern is formed on each ceramic sheet, and the metal pattern is sequentially connected through a plurality of conductive vias provided on each ceramic sheet, Overall, it has one electrical connection structure.

The multilayer inductor is not only suitable for mass production due to the structure as described above, but also has high frequency characteristics superior to those of the wire wound inductor.

However, the laminated inductor has a low saturation magnetization value of the material constituting the metal pattern, and when it is manufactured in a small size, the number of laminated metal patterns is limited. For this reason, there is a problem that the DC superimposition characteristic is lowered and a sufficient current cannot be obtained.

The thin film inductor can be manufactured by forming a thin conductive coil on a coil support layer.

The thin-film inductor can not only use a material having a higher saturation magnetization value than the multilayer inductor, but also has an almost unlimited height even when manufactured in a small size, and easily forms an internal circuit pattern. can do. Therefore, in recent years, research on the thin film inductor has been actively conducted.

In particular, as mobile devices such as smartphones and tablet PCs have higher performance, the display screen is larger and the APU speed is faster, and power consumption is increasing, such as using dual cores or quad cores. Therefore, a thin-film inductor mainly used for a DC-DC converter, a noise filter, or the like is also required to realize a high inductance and a low DC resistance.

With the development of IT technology, miniaturization and thinning of various electronic devices are accelerating. Therefore, thinning and thinning of thin film inductors used in such electronic devices are required.

Korean Registered Patent No. 0167392 Korean Published Patent No. 2006-0102493

In this technical field, the inductor performance can be improved by reducing the size of the coil pad and reducing the size of the via electrode hole to increase the area of the core formed inside the coil. A method has been required.

According to one embodiment of the present invention, a support having first and second metal layers formed thicker than the resin layer on both sides of the resin layer and the resin layer, and the first and second metals. The first and second coils having first and second pad portions formed at one end facing each other and extended from the other portions are connected to the pad portions of the first and second coils. As described above, the support body includes a via electrode formed so as to be vertically penetrated, and a main body in which the first and second coils are embedded, and the first and second metal layers include: An inductor having first and second groove portions at positions corresponding to the first and second pad portions is provided.

The inductor according to an embodiment of the present invention may further include first and second external electrodes formed on the body so as to be connected to the lead portions of the first and second coils.

The first and second coils in an embodiment of the present invention may be spiral.

The inductor according to an embodiment of the present invention may further include an insulating film formed on both sides of the support so as to cover the first and second coils.

The inductor according to an embodiment of the present invention may further include first and second plating layers formed on the first and second coils.

According to another embodiment of the present invention, the first and second metal layers are formed by laminating the first and second metal layers thicker than the resin layer on both surfaces of the resin layer, and forming the support. Forming first and second groove portions at positions facing each other, forming a via electrode so as to penetrate the support at a position where the first and second groove portions are formed, and The first and second pad portions, which are formed by filling the first and second groove portions and extended from the other portions, are connected to the exposed end portions of the via electrode, respectively, at one end portion. Forming a first and second coil in the first and second metal layers, respectively, and forming a body such that the first and second coils are embedded. A method is provided.

The inductor manufacturing method according to another embodiment of the present invention may further include forming first and second external electrodes on the main body so as to be connected to the lead portions of the first and second coils. it can.

In another embodiment of the present invention, the inductor manufacturing method includes forming the first and second coils on the first and second metal layers and then covering the periphery of the first and second coils with an insulating material. And forming an insulating film.

The inductor manufacturing method according to another embodiment of the present invention further includes a step of plating the first and second coils after forming the first and second coils on the first and second metal layers. be able to.

According to one embodiment of the present invention, the inductor pad performance is improved by reducing the size of the pad portion of the coil and reducing the size of the via electrode hole, thereby increasing the area of the core formed inside the coil. Can be made.

FIG. 3 is a cross-sectional view schematically illustrating a cross-section in the width-thickness direction of an inductor according to an embodiment of the present invention. 1 is a plan view illustrating an inductor support and a first coil according to an embodiment of the present invention; It is sectional drawing which expanded and illustrated the A section of FIG. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention. FIG. 4 is a cross-sectional view sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for a clearer description.

Inductor FIG. 1 is a cross-sectional view schematically illustrating a cross-section in the width-thickness direction of an inductor according to an embodiment of the present invention, and FIG. FIG. 3 is a plan view illustrating the first coil, and FIG. 3 is a cross-sectional view illustrating an enlarged portion A of FIG.

Referring to FIGS. 1 to 3, the inductor 10 according to the present embodiment includes a support 40, first and second coils 20 and 30, a via electrode 60, and a main body 11.

The main body 11 may be a substantially rectangular parallelepiped, and can be formed so that the components excluding the lead portions 22 and 32 of the first and second coils 20 and 30 are embedded therein.

First and second external electrodes 51 and 52 are formed on one side of the main body 11, and the first and second external electrodes 51 and 52 are the first and second coils 20 and 30. The lead portions 22 and 32 can be connected to the exposed portions, respectively.

The first and second external electrodes 51 and 52 are selected from the group consisting of metals capable of imparting electrical conductivity, such as gold, silver, platinum, copper, nickel, palladium, and alloys thereof. One or more metals can be included, but the invention is not limited thereto.

At this time, at least one or two of a nickel plating layer (not shown) or a tin plating layer (not shown) are sequentially formed on the surfaces of the first and second external electrodes 51 and 52 as necessary. Can do.

The support 40 includes a resin layer 41 and first and second metal layers 42 and 43 formed on both surfaces of the resin layer 41.

Although the resin layer 41 can be comprised with the board | substrate which consists of insulating materials, such as BT resin and a photosensitive polymer, for example, this invention is not limited to this.

As the substrate, a glass substrate, a ceramic substrate, a semiconductor substrate, or a resin substrate such as an FR4 substrate or a polyimide substrate can be used, but the present invention is not limited to this.

The first and second metal layers 42 and 43 may be made of a metal material such as copper, but the present invention is not limited thereto. In addition, the first and second metal layers 42 and 43 are formed so as to face up and down at positions corresponding to first and second pad portions of first and second coils 20 and 30 described later. It has the 2nd groove parts 42a and 43a.

The first and second coils 20 and 30 can be formed on the first and second metal layers 42 and 43 of the support 40 by various methods such as electroplating and screen printing.

The first and second coils 20 and 30 preferably have a substantially spiral structure, but the present invention is not limited to this. For example, a polygon such as a quadrangle, a pentagon, a hexagon, or a circle The shape may be an ellipse, or may be an irregular shape as necessary.

However, when the main body 11 is a rectangular parallelepiped as in the present embodiment, the first and second coils 20 and 30 are spiral, which minimizes the area of the first and second coils 20 and 30. To maximize the strength of the induced magnetic field.

The first and second coils 20, 30 are formed from the first and second main body parts 21, 31 spirally formed on both surfaces of the support body 40, and the main body 11 from one end of the first and second main body parts 21, 31. The first and second lead portions 22 and 32 drawn through one side surface and electrically connected to the first and second external electrodes 51 and 52, respectively, and the first and second main body portions 21 and 31. 1st and 2nd pad parts 23 and 33 formed extending from other parts at the other end.

The first and second pad portions 23 and 33 are formed in the groove portions 42a and 43a of the first and second metal layers 42 and 43 of the support body 40, respectively, and are arranged to face each other with the support body 40 interposed therebetween. In addition, the first and second pad parts 23 and 33 may have various shapes such as a quadrangle and an ellipse as required.

The first and second coils 20 and 30 may include one or more metals selected from the group consisting of gold, silver, platinum, copper, nickel, palladium, and alloys thereof. Is not limited to this.

In addition, plating layers 71 and 72 may be further formed on the surfaces of the first and second coils 20 and 30 as necessary. Reference numerals 71a and 72a denote grooves formed on the surfaces of the plating layers 71 and 72 by the first and second grooves 42a and 43a of the first and second metal layers 42 and 43 during the plating process.

The via electrode 60 includes the resin layer 41 of the support 40 and the first and second metal layers 42 and 43 at positions corresponding to the first and second groove portions 42 a and 43 a of the first and second metal layers 42 and 43. After forming a through-hole penetrating vertically, the through-hole can be formed by a method such as filling with a conductive paste.

At this time, both end portions exposed above and below the via electrode 60 are connected to and electrically connected to the first and second pad portions 23 and 33 of the first and second coils 20 and 30, respectively.

The conductive paste constituting the via electrode 60 is selected from the group consisting of gold, silver, platinum, copper, nickel, palladium, and alloys thereof, similar to the first and second coils 20 and 30 described above. However, the present invention is not limited thereto.

On the other hand, in order to insulate the main body 11 from the first and second coils 20 and 30, the first and second coils are formed on both surfaces of the support 40, more specifically, on the first and second metal layers 42 and 43. Insulating films 55 may be formed so as to cover 20 and 30, respectively.

The insulating film 55 can be made of a material having insulating characteristics. For example, a filler, a polymer, an acrylate, an epoxy, or the like can be used, but the present invention is not limited to this.

In order to improve the performance (Ls) of the thin film inductor, the area of the core, which is a portion formed inside the coil, must be increased. For this purpose, the pad portion of the coil for forming the via electrode and the hole of the via electrode must be relatively small.

In order to reduce the size of the via electrode hole as described above, it is advantageous to reduce the thickness of the core. However, conventionally, if the thickness of the support is reduced for that purpose, there has been a problem that the support is damaged in the process of drilling holes in the via electrode.

However, according to the present embodiment, the core formed on the inner side of the coil is formed by etching the portion where the via hole is formed to form the groove, thereby reducing the size of the coil pad and reducing the size of the via hole. Since the area of the inductor can be increased, the performance of the inductor can be improved.

In addition, by reducing the via hole as described above, it is possible to reduce the occurrence of an open defect in which a via hole is formed outside the pad portion of the coil due to alignment.

Inductor manufacturing method FIGS. 4a to 4i are cross-sectional views sequentially illustrating a process of forming an inductor support, a coil, and a via electrode according to an embodiment of the present invention.

Hereinafter, an inductor manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. 4A to 4E.

Referring to FIG. 4 a, first, the support 40 is formed by laminating the first and second metal layers 42 and 43 on both surfaces of the resin layer 41.

At this time, the resin layer 41 can be formed of a substrate made of an insulating material such as BT resin or photosensitive polymer, but the present invention is not limited to this. The first and second metal layers 42 and 43 may be made of a metal material such as copper, but the present invention is not limited to this.

4B and 4C, PR (photo resist) 81 and 82 are attached to the surfaces of the first and second metal layers 42 and 43 except for the portions where the grooves are formed. Thereafter, using PR81 and 82 as an etching mask, exposure and etching are performed using an etching solution.

Thereafter, a step such as stripping is performed to make the surfaces of the etched first and second metal layers 42 and 43 uniform, and the first and second groove portions 42a and 43a are formed at positions facing each other vertically.

Next, referring to FIG. 4d, the resin layer 41 and the first and second metal layers 42 of the support 40 are formed at a position where the first and second groove portions 42a and 43a are formed using a laser or a punching machine. A hole is formed so as to penetrate through 43, and the via electrode 60 is formed by filling the hole with a conductive paste.

Next, the first and second coils 20 and 30 are spirally formed on the first and second metal layers 42 and 43 by various methods such as electroplating and screen printing.

4e to 4h, first, conductive layers 210 and 220 are formed on the first and second metal layers 42 and 43, respectively, and spiral PRs 91 and 92 are formed on the portions where the coil is not formed. Form. Thereafter, etching is performed using an etching solution using PR 91 and 92 as an etching mask.

Thereafter, the first and second coils 20 and 30 can be formed in a spiral shape by performing a process such as stripping to make the surfaces of the etched conductive layers 210 and 220 uniform.

At this time, the conductive layers 210 and 220 formed by filling the first and second groove portions 42 a and 43 a of the first and second metal layers 42 and 43 become the first and second pad portions 23 and 33.

The embodiment of the present invention has been described in detail above, but the scope of the present invention is not limited to this, and various modifications and variations can be made without departing from the technical idea of the present invention described in the claims. It will be apparent to those having ordinary knowledge in the art.

DESCRIPTION OF SYMBOLS 10 Inductor 11 Main body 20, 30 1st and 2nd coil 21, 31 1st and 2nd main-body part 22, 32 1st and 2nd drawer | drawing-out part 23, 33 1st and 2nd pad part 40 Support body 41 Resin layer 42 43 First and second metal layers 42a, 43a First and second groove portions 51, 52 First and second external electrodes 55 Insulating film 60 Via electrodes 71, 72 First and second plated layers 210, 220 Conductive layer

Claims (10)

A support having a resin layer and first and second metal layers formed thicker on both sides of the resin layer than the resin layer;
First and second coils formed on the first and second metal layers and having first and second pad portions formed at one end facing each other and expanded from the other portions;
A via electrode formed vertically through the support so as to connect the pad portions of the first and second coils;
A body embedded with the first and second coils,
The inductor according to claim 1, wherein the first and second metal layers have first and second groove portions at positions corresponding to the first and second pad portions. The inductor of claim 1, further comprising first and second external electrodes formed on the body to be connected to the lead portions of the first and second coils. The inductor according to claim 1, wherein the first and second coils are spiral. The inductor according to claim 1, further comprising an insulating film formed on both surfaces of the support so as to cover the first and second coils. The inductor according to claim 1, further comprising first and second plating layers formed on the first and second coils. Forming a support on both surfaces of the resin layer by laminating the first and second metal layers thicker than the resin layer;
Forming first and second groove portions at positions where the first and second metal layers face each other;
Forming a via electrode so as to penetrate the support at a position where the first and second groove portions are formed;
The first and second pad portions, which are formed by filling the first and second groove portions and are extended from the other portions, are connected to the exposed ends of the via electrode, respectively. Forming first and second coils on the first and second metal layers, respectively,
Forming a body such that the first and second coils are embedded. The method of manufacturing an inductor according to claim 6, further comprising forming first and second external electrodes on the main body so as to be connected to lead portions of the first and second coils. . The method of manufacturing an inductor according to claim 6, wherein the first and second coils are spiral. The method further includes forming an insulating film by covering the first and second coils with an insulating material after forming the first and second coils on the first and second metal layers. The method for manufacturing an inductor according to claim 6. The inductor of claim 6, further comprising a step of plating the first and second coils after forming the first and second coils on the first and second metal layers. Production method.

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